ld.so: object '/usr/local/lib/libjemalloc.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored

This error message indicates that the dynamic linker ld.so is unable to preload the shared library libjemalloc.so because it is of the wrong ELF class.

ELF (Executable and Linkable Format) is a standard file format for executables, object code, shared libraries, and core dumps used by many operating systems, including Linux. ELF files come in two main variants: 32-bit and 64-bit.

In this case, it seems that the shared library libjemalloc.so was compiled as a 64-bit ELF file, while the program or library that is trying to load it is a 32-bit binary. As a result, the dynamic linker cannot preload the library and ignores it.

To fix this issue, you would need to make sure that the 32-bit binary is running on a system that supports 64-bit libraries, or recompile the shared library as a 32-bit ELF file if possible. Alternatively, you could try to find a 32-bit version of the library or use a different memory allocator.